potato after inoculation of P. infestans as well as E. carotovora subsp. atroseptica
filtrate (Dellagi et al. 2000). The same results were evidentially supported by the
work of Beyer et al. (2001) upon compatible interaction of P. infestans with the
potato. They identified multiple induced potato genes including S1-9D (WRKY-box
transcription factor-like) during the fungus colonization using SSH, inverse northern
analysis, and RNA blot analysis, For more detailed information, the readers can refer
to the same publication. In another study, Cormack et al. (2002) identified two new
WRKY TFs from parsley, namely WRKY4 and WRKY5 using the Y1-hybrid system.
Furthermore, Pep25 elicitor treatment increased the transient expression of the
WRKY5 gene, a group III family member. Additionally, their results for other
WRKY TFs such as WRKY1 and WRKY3 were following the results of Rushton
et al. (1996). In Arabidopsis thaliana (Ecotype Columbia and Landsberg erecta), the
transient expression time-course kinetics for a total of 13 WRKY group members
were analyzed upon Peronospora parasitica and Blumeria graminis f. sp. hordei in
both compatible and incompatible interactions. Their findings indicated that the
WRKY TFs such as WRKY38, WRKY54, WRKY55, WRKY66, WRKY67, and
WRKY70 upregulated in susceptible Ler-1 plants (Kalde et al. 2003). Similarly, the
CaWRKY31 gene was found to be upregulated in coffee upon coffee rust fungus
(Hemileia vastatrix) infection (Fernandez et al. 2004). In another work, they confirmed the upregulation in the transcripts level of CaWRKY1 upon inoculation of
coffee rust fungus (Kenyan isolate 1427) (Ganesh et al. 2006).
The arbuscular mycorrhiza colonization-induced changes in the whole rice
transcriptome were compared upon with changes induced by two devastating
pathogens, M. grisea and Fusarium moniliforme, and reported over 40% changes.
Among the total mycorrhiza-regulated genes, about 30 genes including OsAM205, a
WRKY-encoding gene was differentially expressed in a similar way upon AM and
pathogen colonization reflects a general plant response to fungi colonization (Guimil
et al. 2005). Ryu and colleagues in 2006 confirmed the changes in the expression
level of total of 15 host WRKY genes upon inoculation of M. grisea (Philippines
isolate PO6-6). Their extensive profiling analysis work revealed that the transcript
levels of OsWRKY7, OsWRKY10, OsWRKY11, OsWRKY30, OsWRKY45,
OsWRKY62, OsWRKY76, OsWRKY82, and OsWRKY85 were significantly increased
by 6–48 h. The positive role of AtWRKY33 in plant immunity against necrotrophic
fungi such as Alternaria brassicicola and B. cinerea was confirmed with gain- and
loss-of-function studies (Zheng et al. 2006). Using the model plant A. thaliana, the
physical interaction and complex regulatory role of AtWRKY18, AtWRKY40, and
AtWRKY60 in B. cinerea resistance was deduced (Xu et al. 2006). The role of the
so-called SA activator, namely benzothiadiazole is well depicted in the literature.
Using the group of techniques like microarray screening, RNAi, and transient
overexpression system, the role of BTH-inducible WRKY45 was identified in
providing resistance against rice blast disease (Shimono et al. 2007). The same
type of results upon overexpression of AtWRKY70 in A. thaliana confirmed the
RPP4-based resistance against Hyaloperonospora parasitica (Knoth et al. 2007).
The positive role of nuclear-localized, rapidly inducing AtWRKY3 and AtWRKY4 in
PR1-based immunity against the necrotrophic fungus B. cinerea was revealed using
11 Role of WRKY Transcription Factor Superfamily in Plant Disease Management
349
filtrate (Dellagi et al. 2000). The same results were evidentially supported by the
work of Beyer et al. (2001) upon compatible interaction of P. infestans with the
potato. They identified multiple induced potato genes including S1-9D (WRKY-box
transcription factor-like) during the fungus colonization using SSH, inverse northern
analysis, and RNA blot analysis, For more detailed information, the readers can refer
to the same publication. In another study, Cormack et al. (2002) identified two new
WRKY TFs from parsley, namely WRKY4 and WRKY5 using the Y1-hybrid system.
Furthermore, Pep25 elicitor treatment increased the transient expression of the
WRKY5 gene, a group III family member. Additionally, their results for other
WRKY TFs such as WRKY1 and WRKY3 were following the results of Rushton
et al. (1996). In Arabidopsis thaliana (Ecotype Columbia and Landsberg erecta), the
transient expression time-course kinetics for a total of 13 WRKY group members
were analyzed upon Peronospora parasitica and Blumeria graminis f. sp. hordei in
both compatible and incompatible interactions. Their findings indicated that the
WRKY TFs such as WRKY38, WRKY54, WRKY55, WRKY66, WRKY67, and
WRKY70 upregulated in susceptible Ler-1 plants (Kalde et al. 2003). Similarly, the
CaWRKY31 gene was found to be upregulated in coffee upon coffee rust fungus
(Hemileia vastatrix) infection (Fernandez et al. 2004). In another work, they confirmed the upregulation in the transcripts level of CaWRKY1 upon inoculation of
coffee rust fungus (Kenyan isolate 1427) (Ganesh et al. 2006).
The arbuscular mycorrhiza colonization-induced changes in the whole rice
transcriptome were compared upon with changes induced by two devastating
pathogens, M. grisea and Fusarium moniliforme, and reported over 40% changes.
Among the total mycorrhiza-regulated genes, about 30 genes including OsAM205, a
WRKY-encoding gene was differentially expressed in a similar way upon AM and
pathogen colonization reflects a general plant response to fungi colonization (Guimil
et al. 2005). Ryu and colleagues in 2006 confirmed the changes in the expression
level of total of 15 host WRKY genes upon inoculation of M. grisea (Philippines
isolate PO6-6). Their extensive profiling analysis work revealed that the transcript
levels of OsWRKY7, OsWRKY10, OsWRKY11, OsWRKY30, OsWRKY45,
OsWRKY62, OsWRKY76, OsWRKY82, and OsWRKY85 were significantly increased
by 6–48 h. The positive role of AtWRKY33 in plant immunity against necrotrophic
fungi such as Alternaria brassicicola and B. cinerea was confirmed with gain- and
loss-of-function studies (Zheng et al. 2006). Using the model plant A. thaliana, the
physical interaction and complex regulatory role of AtWRKY18, AtWRKY40, and
AtWRKY60 in B. cinerea resistance was deduced (Xu et al. 2006). The role of the
so-called SA activator, namely benzothiadiazole is well depicted in the literature.
Using the group of techniques like microarray screening, RNAi, and transient
overexpression system, the role of BTH-inducible WRKY45 was identified in
providing resistance against rice blast disease (Shimono et al. 2007). The same
type of results upon overexpression of AtWRKY70 in A. thaliana confirmed the
RPP4-based resistance against Hyaloperonospora parasitica (Knoth et al. 2007).
The positive role of nuclear-localized, rapidly inducing AtWRKY3 and AtWRKY4 in
PR1-based immunity against the necrotrophic fungus B. cinerea was revealed using
11 Role of WRKY Transcription Factor Superfamily in Plant Disease Management
349